Catalyst for cross-coupling reactions

ABSTRACT

A catalyst system, in particular for carrying out cross-coupling reactions is obtainable by reacting 
     a) a palladium(II) compound with 
     b) a water-soluble phosphine ligand and 
     c) a sulfoxide or polyhydric alcohol.

The invention relates to a palladium catalyst comprising a water-solublephosphine ligand, preferably for carrying out cross-coupling reactions,a process for its preparation and also its use in cross-couplingreactions.

Cross-coupling reactions of aromatic boron compounds, e.g. boronicacids, and aromatic halogen compounds or perfluoroalkylsulfonates havefor some years been used to an increasing extent for building uppolycyclic aromatic systems. For example, such processes are used forproducing active compounds for pharmaceuticals and components of liquidcrystal mixtures.

However, the catalysts customarily used, e.g. Pd[P(Ph₃)]₄ or PdCl₂(4PPh₃)4NaBH₄, give the coupling products in appreciable yields onlywhen bromoaromatics or iodoaromatics are employed. The high costs ofthese starting compounds make economical scale-up of the processes to aproduction scale difficult.

EP-A 0 372 313 discloses palladium catalysts comprising water-solublephosphine ligands which are used, for example, in the cross-couplingreaction of alkynes with allenes.

The systems described always contain palladium in the oxidation state(0).

EP-A 0 694 530 describes a process for preparing polycyclic aromaticcompounds by cross-coupling aromatic boron compounds with aromatichalogen compounds or aromatic perfluoroalkylsulfonates using palladiumcatalysis in the presence of at least one water-soluble complexingligand, wherein the reaction medium comprises an aqueous phase and anorganic phase and the palladium is added in the form of a palladiumcompound soluble in the organic phase.

Although very good results are achieved using this process, there isstill room for improvements, particularly with regard to the use ofinexpensive chloroaromatics as starting material.

It has now surprisingly been found that palladium catalysts having aparticularly high activity can be prepared by reaction of palladium(II)compounds, water-soluble phosphine ligands and a sulfoxide or apolyhydric alcohol.

The present invention accordingly provides a catalyst system, inparticular for carrying out cross-coupling reactions, obtainableby-reacting

a) a palladium(II) compound with

b) a water-soluble phosphine ligand and

c) a sulfoxide or polyhydric alcohol.

The invention further provides a process for preparing a catalystsystem, in particular for carrying out cross-coupling reactions, whichcomprises reacting

a) a palladium(II) compound with

b) a water-soluble phosphine ligand and

c) a sulfoxide or polyhydric alcohol.

The invention likewise provides for the use of a catalyst systemobtainable by reacting

a) a palladium(II) compound with

b) a water-soluble phosphine ligand and

c) a sulfoxide or polyhydric alcohol for carrying out cross-couplingreactions.

Catalyst systems according to the invention have a particularly highactivity and it is possible to use them a plurality of times. They arealso suitable, in particular, for coupling reactions in whichchloroaromatics can be used as starting materials.

Suitable components a are palladium(II) compounds, preferablypalladium(II) salts, tetrachloropalladic acid or its salts, preferablyalkali metal salts. Preferred compounds are, for example, palladiumacetylacetonates, palladium halides, allylpalladium halides andpalladium biscarboxylates, particularly preferably palladiumacetylacetonates, palladium(II) halides, tetrachloropalladic acid andits salts.

Compounds which are very particularly suitable as component a arePd(II)Cl₂ /3 NaOAc, Pd(ac)₂, K₂ PdCl₄, Na₂ PdCl₄, K₂ Pd₂ Cl₆, Na₂ Pd₂Cl₆ and H₂ PdCl₄.

It is naturally also possible to use mixtures of two or more palladiumcompounds as component a.

In a preferred embodiment of the invention, the catalyst systemcomprises one or more additives such as sodium acetate which act assolubilizer for the palladium compound in the system sulfoxide orpolyhydric alcohol and, if desired, water. Particular preference isgiven to using sodium acetate, in particular in a molar ratio of from 1to 4, preferably 3, based on the palladium compound.

Suitable water-soluble phosphine ligands are tri-n-alkylphosphines,triarylphosphines, dialkylarylphosphines, alkyldiarylphosphines andheteroarylphosphines preferably provided with carboxylate or carboxylicacid, ammonium, phosphonium, sulfonate or sulfonic acid, phosphonate orphosphonic acid groups or with polyalcohols having a suitable number ofhydroxy functions or polyalkylene glycols having a suitable chainlength, where the three substituents on the phosphorus can be identicalor different and chiral or achiral and one or more of the substituentscan link the phosphorus groups of a plurality of phosphines and part ofthis linkage can also be one or more metal atoms.

Particular preference is given to using water-soluble phosphines whichhave at least one aryl group on the phosphorus, i.e. triarylphosphines,diarylalkylphosphines and dialkylarylphosphines.

Particular preference is given to using water-soluble phosphines of theformulae (I) to (VII), ##STR1## where the symbols and indices have thefollowing meanings: Aryl: a phenyl or naphthyl group which may also bearone or more substituents R;

Alkyl: a straight-chain or branched alkyl group having from 1 to 8carbon atoms;

R,R': alkyl, aryl or aralkyl having from 1 to 18 carbon atoms;

M: alkali metal, alkaline earth metal or NR₄ ;

X: halogen, BF₄, OSO₂ CF₃, 1/2[SO₄ ];

I,m: 1 to 8;

n,o,p,q: 0, 1 to 8;

s: 0, 1 to 3.

Examples of particularly preferred water-soluble complexing ligands areshown below:

(R is, unless indicated otherwise, as defined for the formulae (I) to(VII))

1. Sulfonated Phosphines ##STR2## R_(3-n) P(p-C₆ H₄ SO₃ K)_(n) R=C₆ H₅,2-Pyridyl, 3-Pyridyl; n=1-3 P[p-OC₆ H₄ SO₃ (NH(i-octyl)₃ ]₃ ##STR3##

2. Phosphines Having Quatemized Aminoalkyl and Aminoaryl Substituents##STR4## Y=--CH₂ CH₂ --, --CH(CH₃)CH₂ --, --CH₂ CH(CH₃)CH₂ --; R=CH₃ ;X=I.sup.⊖, Bu.sup.⊖, Cl.sup.⊖, OSO₂ CF₃.sup.⊖, BF₄.sup.⊖

3. Carboxylated Phosphines ##STR5## Very particular preference is givento: ##STR6##

It is naturally also possible to use a plurality ofphosphorus-containing ligands.

The phosphorus-containing ligands used according to the invention areknown per se. Some of them are available as commercial products or theyare described together with their synthesis in, for example,Houben-Weyl, Methoden der Organischen Chemie, Georg-Thieme-Verlag,Stuttgart.

Water-soluble ligands can be prepared, for example, by the method of W.A. Herrmann and C. W. Kohipainter, Angew. Chem. Int. Ed. Engl. 1993, 32,1524 or the literature cited therein. The preparation of BINAS isdescribed in EP-A 0 571 819 or U.S. Pat. No. 5,347,045. An aqueous 0.6molar solution of the trisodium salt of TPPTS is commercially available(Hoechst AG, Germany).

According to the invention, the phosphorus-containing ligand is used ina ratio of from 1 to 20 phosphorus equivalents, preferably from 2 to 12,particularly preferably from 2 to 6, very particularly preferably 4,based on the Pd compounds.

Preferred polyhydric alcohols are those which are water-soluble.Particular preference is given to glycols, glycerol, oligoglycerideswhich may also be partially esterified, diethylene, triethylene andtetraethylene glycols or polyethylene glycols or the formula (VIII),##STR7## polyhydric alkanols or alkenols such as 1,4-butanediol,1,3-propanediol, 1,2-propanediol, pentaerythritol,2-ethylhexane-1,3-diol, 2-(hydroxymethyl)-2-methyl-1,3-propanediol,2-methyl-2,4-pentanediol, 1,4-cis-butenediol, polyhydric cycloalkanolssuch as cyclohexanediol, polyhydric alkanols containing aryl groups,e.g. 1-phenyl-1,2-ethanediol, polyhydric aminoalcohols such asdiethanolamine, triethanolamine, 2-amino-2-methyl-1,3-propanediol,3-(aminomethyl)-1,2-propanediol, 3-amino-1,2-propanediol,2-amino-1,3-propanediol oxalate, 3-(diethylamino)-1,2-propanediol,ethylenediamine-N,N,N',N'-tetra-2-propanediol, polyhydric iminoalcohols,such as N-butyl-2,2'-iminodiethanol andN-tert.-butyl-2,2'-iminodiethanol, 1,1'-iminodi-3-propanol,N-methyl-2,2'-iminodiethanol, N-phenyl-2,2'-iminodiethanol or compoundssuch as 1,1',1"-nitrilotri-2-propanol,1,3,5-tri(2-hydroxyethyl)isocyanuric acid and dihydroxyacetone.

Very particular preference is given to glycol, glycerol, 1,4-butanediol,1,2-propanediol, triethylene glycol, diethylene glycol, diethanolamineand triethanolamine and among these particularly glycol, glycerol,1,4-butanediol and 1,2-propanediol.

It is naturally also possible to use a plurality of polyhydric alcohols.

Preferred sulfoxides are those of the formula (IX): ##STR8##

R¹, R² are aliphatic or aromatic hydrocarbons which may, if desired, besubstituted or linked to one another.

Particularly preferred sulfoxides are dimethyl sulfoxide (DMSO),diphenyl sulfoxide, methyl phenyl sulfoxide and dibenzyl sulfoxide.

Preference is given to using water-soluble sulfoxides. A particularlypreferred water-soluble sulfoxide is DMSO.

It is naturally also possible to use a plurality of sulfoxides or theirmixtures, if desired also with polyhydric alcohols.

The polyhydric, water-soluble alcohols or the sulfoxide are preferablyadded in a weight ratio of from 0.1 to 10,000, based on thepalladium(II) compound.

The catalyst system of the present invention preferably comprises water,for example by addition of the phosphine ligands as aqueous solution.

The preparation of the catalyst system of the invention can be carriedout according to different variants.

The palladium compound can first be dissolved, for example by dissolvingit in the sulfoxide or the polyhydric alcohol with the aid of additivessuch as sodium acetate, and subsequently be reacted with the phosphineligand dissolved in water, to form the catalyst system of the invention.However, the catalyst system is also formed when the individualcomponents are mixed at the same time.

To use the catalyst system of the invention, preference is given todissolving the palladium(II) compound in a polyhydric alcohol orsulfoxide, preferably DMSO or glycol, adding the water-soluble phosphineligand or a solution thereof and adding the resulting catalyst solutionto the remaining reactants.

Preference is likewise given to dissolving palladium or a palladiumcompound in a polyhydric alcohol or sulfoxide, preferably DMSO orglycol, adding the remaining reactants to this solution and subsequentlyadding the water-soluble phosphine ligand or a solution thereof.

Preference is also given to initially charging the palladium(II)compound, for example in aqueous solution, adding the water-solublephosphine ligand, if desired as solution, and adding this solution to amixture of the starting materials, if desired a solvent and thepolyhydric alcohol or sulfoxide.

Catalyst systems according to the invention preferably have broadsignals of from 36 to 32 ppm and from 8 to 4 ppm in the ³¹ P-NMRspectrum (with virtual referencing to external 85% phosphoric acid,Bruker DRX 400 spectrometer).

The catalyst systems of the invention display the following reactions:telomerizations, addition of CH-acid compounds onto butadiene,hydrogenations, reactions of nitro compounds, preferably nitroaromatics.

They are therefore used as catalyst in such reactions.

Preference is given to the use as catalyst for carbon-carbon linkagereactions, in particular for the cross-coupling reaction of boronicacids with halogen compounds, preferably aromatic halogen compounds, inparticular chloroaromatics.

By way of example, the use of catalyst systems according to theinvention for cross-coupling reactions of aromatic boronic acids withhaloaromatics is described below.

This reaction comprises reacting

a) an aromatic boron compound with

b) an aromatic halogen compound or an aromatic perfluoroalkylsulfonatein the presence of

c) a base and

d) a catalyst system according to the invention.

The catalyst system of the invention is used in the process in an amountof from 0.001 to 10 mol %, preferably from 0.01 to 5 mol %, particularlypreferably from 0.05 to 3 mol %, very particularly preferably from 0.05to 1.5 mol %, based on the aromatic halogen compound or the aromaticperfluoroalkylsulfonate.

Bases which are usually used in the process are alkali metal fluorides,alkali metal and alkaline earth metal hydroxides, alkali metal andalkaline earth metal carbonates, alkali metal hydrogen carbonates,alkali metal and alkaline earth metal acetates, alkali metal andalkaline earth metal alkoxides, and also primary, secondary and tertiaryamines.

Particular preference is given to alkali metal fluorides, alkali metaland alkaline earth metal hydroxides, alkali metal and alkaline earthmetal carbonates and alkali metal hydrogen carbonates. Very particularpreference is given to alkali metal fluorides such as potassium fluorideand cesium fluoride, alkali metal hydroxides such as sodium hydroxideand potassium hydroxide, and also alkali metal carbonates and alkalimetal hydrogen carbonates, e.g. lithium carbonate, sodium carbonate andpotassium carbonate.

When using solid bases such as Na₂ CO₃, the polyhydric alcohol or thesulfoxide is preferably used in relatively large amounts or as solventin order to achieve appropriate suspension of the base and thus astirrable mixture.

It is naturally also possible to use a plurality of bases.

The base is preferably used in an amount of from 100 to 1000 mol %,particularly preferably from 100 to 500 mol %, very particularlypreferably from 100 to 400 mol %, in particular from 100 to 290 mol %,based on the aromatic boron compound.

Preferred starting compounds are, on the one hand, aromatic boroncompounds of the formula (XI),

    Aryl--BQ.sub.1 Q.sub.2                                     (XI)

where

Aryl is an aromatic radical and

Q₁, Q₂ are identical or different and are --OH, C₁ -C₄ -alkoxy, C₁ -C₄-alkyl, phenyl, which may bear C₁ -C₄ -alkyl, C,-C₄ -alkoxy or halogensubstituents, or halogen or Q₁ and Q₂ together form a C₁ -C₄-alkylenedioxy group or a methylene group which may bear one or two C₁-C₄ -alkyl groups as substituents, or Q₁ and Q₂ and the boron atom aretogether part of a boroxane ring of the formula (XI): ##STR9## whereAryl is preferably a phenyl, naphthyl, pyrimidyl, pyridyl, pyrazinyl,pyradiazinyl, 1,3-thiazolyl, 1,3,4-thiadiazolyl or thiophenyl radical,each of which may be unsubstituted or substituted, for example byhalogen, cyano, alkyl or alkoxy groups.

Preferably,

Q₁, Q₂ are identical or different and are --OH, C₁ -C₄ -alkoxy orhalogen or Q₁ and Q₂ together form a C₁ -C₄ -alkylenedioxy group or Q₁and Q₂ and the boron atom are together part of a boroxane ring of theformula (XI): ##STR10##

Particularly preferably, Aryl is an unsubstituted or substituted phenylor naphthyl group.

The aromatic boron compounds used are either known or they can beprepared by methods known per se, as are described, for example, inHouben Weyl, Methoden der Organischen Chemie, Georg Thieme-Verlag,Stuttgart, Volume 13/3a. Thus, for example, boronic acids can beobtained from aromatic alkali metal and magnesium compounds by reactionwith trialkoxyboranes and subsequent hydrolysis.

The second class of starting compounds for the process are aromaticcompounds of the formula (XII)

    Aryl--X                                                    (XII)

where

Aryl is an aromatic radical and

X is Cl, Br, I or a perfluoroalkysulfonate.

X is preferably Cl.

Aryl is preferably an unsubstituted or substituted phenyl, naphthyl,pyridyl, pyrimidyl, pyrazinyl, pyridiazinyl, 1,3-thiazolyl,1,3,4-thiadiazolyl or thiophenyl radical, where the substituent orsubstituents is/are, for example, halogen, CN, alkyl, alkoxy or furtheraryl groups.

The aromatic halogen compounds and perfluoroalkylsulfonates used areeither known or can be prepared by known methods, as are described, forexample, in Houben Weyl, Methoden der Organischen Chemie, Georg ThiemeVerlag, Stuttgart, Volume 5/3 and 5/4. For example, aromatic halides canbe obtained by replacing the diazonium group in an appropriate diazoniumsalt by chlorine, bromine or iodine.

Furthermore, hydroxy-substituted nitrogen heterocycles can be convertedinto the corresponding halides by means of phosphorus trihalides andphosphorus oxytrihalides.

To carry out the process, the starting materials, the base and thecatalyst system of the invention are mixed according to theabovementioned variants and reacted at a temperature of from 0 to 200°C., preferably from 30 to 170° C., particularly preferably from 50 to150° C., for a period of from 1 to 100 hours, preferably from 5 to 70hours, particularly preferably from 5 to 50 hours.

The work-up is carried out by known methods with which those skilled inthe art are familiar. For example, the product can be separated form thereaction mixture by extraction or precipitation and subsequently befurther purified by methods matched to the respective product, forexample recrystallization, distillation, sublimation, zone melting, meltcrystallization or chromatography.

The compounds prepared in this way are suitable for use as liquidcrystal materials or can be used as intermediates for the preparation offurther liquid crystal compounds. Furthermore, they are used asprecursors for pharmaceuticals, cosmetics, fungicides, herbicides,insecticides, dyes, detergents and polymers, including additives forthese.

Various documents have been cited in the present application for exampleto illustrate the technical field of the invention. All these documentsare incorporated by reference into the present application.

The subject matter of the German Patent Applications 195 271 18.1, 195355 28.8 and 196 200 23.7, whose priority is claimed by the presentapplication, and also the abstract of the present application are herebyexpressly incorporated by reference into the present application:

The invention is illustrated by the examples, without being restrictedthereby.

EXAMPLES Example 1

0.388 g of palladium(II) chloride and 0.54 g of sodium acetate aredissolved in 24 ml of DMSO. The mixture is stirred for 30 minutes atroom temperature. 14.6 ml of TPPTS/H₂ O solution (0.6 mol/l) aresubsequently added and the mixture is stirred for another 30 minutes.

Example 2

0.388 g of palladium(II) chloride and 0.54 g of sodium acetate aredissolved in 24 ml of ethylene glycol. The mixture is stirred foranother 30 minutes at room temperature. 14.6 ml of TPPTS/H₂ O solution(0.6 mol/l) are subsequently added and the mixture is stirred foranother 30 minutes.

Example 3

1.069 g of tetrachloropalladic acid (20% by weight of palladium inwater) are diluted with 24 ml of water and subsequently admixed with14.6 ml of a 0.6 molar TPPTS/H₂ O solution. The mixture is stirred foranother 30 minutes. 50 ml of ethylene glycol are subsequently added.

Immediately after being made up, the solutions display broad signals atfrom 36 to 32 ppm and from 8 to 4 ppm in the ³¹ P-NMR spectrum.Referencing was virtual, based on external 85% of phosphoric acid. Thespectrometer was a DRX 400 from Bruker.

Use Examples

The mole percentages given for the catalyst solutions refer to thePd(III) content of the catalyst solution and are based on the halogencompound.

Use Example 1

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 1 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 19 g of 2-cyano-4'-methylbiphenyl (b.p. 140° C./mbar).

Comparative Experiment

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of Pd(O)(TPPTS)₃. 9H₂ O dissolved in 3 mlof H₂ O was added. The reaction mixture was held at 120° C. for 12hours. After cooling, 50 ml of xylene were added and the organic phasewas separated off. Distillation gave 10.5 g of 2-cyano-4'-methylbiphenyl(b.p. 140° C./mbar).

Use Example 2

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 2 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 18.5 g of 2-cyano-4'-methylbiphenyl (b.p. 140°C./mbar).

Use Example 3

Preparation of the Catalyst Solution: 0.388 g of palladium(II) chlorideand 14.6 ml of TPPTS/H₂ O solution (0.6 mol/l) were stirred at roomtemperature for 60 minutes. This gave a yellow reaction solution of##STR11##

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of an above-described catalyst solution wasadded. After the reaction was complete, 50 ml of xylene were added andthe organic phase was separated off. Distillation gave 18.7 g of2-cyano-4'-methylbiphenyl (b.p. 140° C./mbar).

Use Example 4

Preparation of the Catalyst Solution

0.388 g of palladium(II) chloride and 0.33 g of potassium chloride weredissolved in 10 ml of water. 14.6 ml of TPPTS/H₂ O solution (0.6 mol/l)were subsequently added.

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of an above-described catalyst solution wasadded. After the reaction was complete, 50 ml of xylene were added andthe organic phase was separated off. Distillation gave 18.1 g of2-cyano-4'-methylbiphenyl (b.p. 140° C./mbar).

Use Example 5

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 3 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 19 g of 2-cyano-4'-methylbiphenyl (b.p. 140° C./mbar).

Use Example 6

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 12 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 1 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 18.5 g of 2-cyano-4'-methylbiphenyl (b.p. 140°C./mbar).

Use Example 7

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 12 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 3 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 18.7 g of 2-cyano-4'-methylbiphenyl (b.p. 140°C./mbar).

Use Example 8

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 12 gof sodium carbonate in 40 ml of glycol and 10 ml of water were heated to120° C. At 80° C., 0.1 mol % of a catalyst solution prepared asdescribed in Example 2 was added. After the reaction was complete, 50 mlof xylene were added and the organic phase was separated off.Distillation gave 18.1 g of 2-cyano-4'-methylbiphenyl (b.p. 140°C./mbar).

Use Example 9

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.9 g of2-cyano-4'-methylbiphenyl.

Use Example 10

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycerol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.5 g of2-cyano-4'-methylbiphenyl.

Use Example 11

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7mg of palladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO was added.

After the reaction was complete, the phases were separated. The aqueousphase was washed with 50 ml of toluene. The combined organic phases werewashed with 20 ml of water and subsequently dried over sodium sulfate.Crystallization from n-heptane gave 17.4 g of 2-cyano-4'-methylbiphenyl.

Use Example 12

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethylene glycol and10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.2 g of2-cyano-4'-methylbiphenyl.

Use Example 13

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethanolamine and 10ml of water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.5 g of2-cyano-4'-methylbiphenyl.

Use Example 14

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.8 g of2-cyano-4'-methylbiphenyl.

Use Example 15

15 g of 2-chlorobenzonitrile, 15.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of glycerol and 10 mlof water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.2 g of2-cyano-4'-methylbiphenyl.

Use Example 16

15 g of 2-chlorobenzonitrile, 15.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of glycol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.7 g of2-cyano-4'-methylbiphenyl.

Use Example 17

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of diethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7mg of palladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.8 g of2-cyano-4'-methylbiphenyl.

Use Example 18

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of triethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7mg of palladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.2 g of2-cyano-4'-methylbiphenyl.

Use Example 19

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of diethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 16.9 g of2-cyano-4'-methylbiphenyl.

Use Example 20

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of triethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5ml of DMSO was added. After the reaction was complete, the phases wereseparated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.2 g of2-cyano-4'-methylbiphenyl.

Use Example 21

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 38.66 mg ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.5 g of2-cyano-4'-methylbiphenyl.

Use Example 22

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycerol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 38.66 mg ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.2 g of2-cyano-4'-methylbiphenyl.

Use Example 23

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66g of palladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6molar) in 2.5 ml of DMSO was added. After the reaction was complete, thephases were separated. The aqueous phase was washed with 50 ml oftoluene. The combined organic phases were washed with 20 ml of water andsubsequently dried over sodium sulfate. Crystallization from n-heptanegave 17.4 g of 2-cyano-4'-methylbiphenyl.

Use Example 24

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethylene glycol and10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66 g ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.1 g of2-cyano-4'-methylbiphenyl.

Use Example 25

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethanolamine and 10ml of water were heated to 120° C. At 80° C., a mixture of 38.66 g ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.5 g of2-cyano-4'-methylbiphenyl.

Use Example 26

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66 g ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.8 g of2-cyano-4'-methylbiphenyl.

Use Example 27

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of glycerol and 10 mlof water were heated to 120° C. At 80° C., a mixture of 38.66 mg ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.9 g of2-cyano-4'-methylbiphenyl.

Use Example 28

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of glycol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 38.66 mg ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.8 g of2-cyano-4'-methylbiphenyl.

Use Example 29

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of diethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66mg of palladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6molar) in 2.5 ml of DMSO was added. After the reaction was complete, thephases were separated. The aqueous phase was washed with 50 ml oftoluene. The combined organic phases were washed with 20 ml of water andsubsequently dried over sodium sulfate. Crystallization from n-heptanegave 18.0 g of 2-cyano-4'-methylbiphenyl.

Use Example 30

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of triethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66mg of palladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6molar) in 2.5 ml of DMSO was added. After the reaction was complete, thephases were separated. The aqueous phase was washed with 50 ml oftoluene. The combined organic phases were washed with 20 ml of water andsubsequently dried over sodium sulfate. Crystallization from n-heptanegave 16.9 g of 2-cyano-4'-methylbiphenyl.

Use Example 31

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of diethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66 mgof palladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 17.1 g of2-cyano-4'-methylbiphenyl.

Use Example 32

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 15.8 gof potassium fluoride in 50 ml of p-xylene, 40 ml of triethanolamine and10 ml of water were heated to 120° C. At 80° C., a mixture of 38.66 mgof palladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of toluene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. Crystallization from n-heptane gave 18.0 g of2-cyano-4'-methylbiphenyl.

Use Example 33

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycol and 10 ml ofwater were heated to 120° C. At 80° C., 19.3 mg of palladium chloride,17.9 mg of sodium acetate and 0.55 ml of TPPTS/H₂ O solution (0.6 molar)in 2.5 ml of DMSO were added. After the reaction was complete, thephases were separated. The aqueous phase was washed with 50 ml oftoluene. The combined organic phases were washed with 20 ml of water andsubsequently dried over sodium sulfate. Crystallization from n-heptanegave 18.7 g of 2-cyano-4'-methylbiphenyl.

Use Example 34

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of glycerol and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 19.3 mg ofpalladium chloride, 17.9 mg of sodium acetate and 0.55 ml of TPPTS/H₂ Osolution (0.6 molar) in 2.5 ml of DMSO was added. After the reaction wascomplete, the phases were separated. The aqueous phase was washed with50 ml of toluene. The combined organic phases were washed with 20 ml ofwater and subsequently dried over sodium sulfate. Crystallization fromn-heptane gave 18.3 g of 2-cyano-4'-methylbiphenyl.

Use Example 35

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethylene glycoland 10 ml of water were heated to 120° C. At 80° C., a mixture of 19.3mg of palladium chloride, 17.9 mg of sodium acetate and 0.55 ml ofTPPTS/H₂ O solution (0.6 molar) in 2.5 ml of DMSO was added. After thereaction was complete, the phases were separated. The aqueous phase waswashed with 50 ml of toluene. The combined organic phases were washedwith 20 ml of water and subsequently dried over sodium sulfate.Crystallization from n-heptane gave 17.4 g of 2-cyano-4'-methylbiphenyl.

Use Example 36

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethylene glycol and10 ml of water were heated to 120° C. At 80° C., a mixture of 19.3 mg ofpalladium chloride, 17.9 mg of sodium acetate and 0.55 ml of TPPTS/H₂ Osolution (0.6 molar) in 2.5 ml of DMSO was added. After the reaction wascomplete, the phases were separated. The aqueous phase was washed with50 ml of toluene. The combined organic phases were washed with 20 ml ofwater and subsequently dried over sodium sulfate. Crystallization fromn-heptane gave 18.3 g of 2-cyano-4'-methylbiphenyl.

Use Example 37

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of diethanolamine and 10ml of water were heated to 120° C. At 80° C., a mixture of 19.3 mg ofpalladium chloride, 17.9 mg of sodium acetate and 0.55 ml of TPPTS/H₂ Osolution (0.6 molar) in 2.5 ml of DMSO was added. After the reaction wascomplete, the phases were separated. The aqueous phase was washed with50 ml of toluene. The combined organic phases were washed with 20 ml ofwater and subsequently dried over sodium sulfate. Crystallization fromn-heptane gave 17.5 g of 2-cyano-4'-methylbiphenyl.

Use Example 38

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of triethanolamine and10 ml of water were heated to 120° C. At 80° C., 19.3 mg of palladiumchloride, 17.9 mg of sodium acetate and 0.55 ml of TPPTS/H₂ O solution(0.6 molar) in 2.5 ml of DMSO were added. After the reaction wascomplete, the phases were separated. The aqueous phase was washed with50 ml of toluene. The combined organic phases were washed with 20 ml ofwater and subsequently dried over sodium sulfate. Crystallization fromn-heptane gave 17.8 g of 2-cyano-4'-methylbiphenyl.

Use Example 39

15 g of 2-chlorobenzonitrile, 14,8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of DMSO and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 24.7 mg ofpalladium(II) acetate and 0.55 ml of TPPTS/H₂ O (0.6 molar) in 2.5 ml ofDMSO was added.

After the reaction was complete, the phases were separated. The aqueousphase was washed with 50 ml of xylene. The combined organic phases werewashed with 20 ml of water and subsequently dried over sodium sulfate.The solvent was evaporated and the residue was crystallized formn-heptane. Yield: 18.6 g (88% of theory) of 2-cyano-4'-methylbiphenyl.

Use Example 40

15 g of 2-chlorobenzonitrile, 14,8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of DMSO and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 38.66 mg ofpalladium(II) chloride and 1.1 ml of TPPTS/H₂ O solution (0.6 molar) in2.5 ml of DMSO was added. After the reaction was complete, the phaseswere separated. The aqueous phase was washed with 50 ml of xylene. Thecombined organic phases were washed with 20 ml of water and subsequentlydried over sodium sulfate. The solvent was evaporated and the residuewas crystallized from n-heptane. Yield: 18.2 g (86% of theory) of2-cyano-4'-methylbiphenyl.

Use Example 41

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene, 40 ml of DMSO and 10 ml ofwater were heated to 120° C. At 80° C., a mixture of 19.3 mg ofpalladium(II) chloride, 17.9 mg of sodium acetate and 0.55 ml ofTPPTS/H₂ O solution (0.6 molar) in 2.5 ml of DMSO was added. After thereaction was complete, the phases were separated. The aqueous phase waswashed with 50 ml of xylene. The combined organic phases were washedwith 20 ml of water and subsequently dried over sodium sulfate. Thesolvent was evaporated and the residue was crystallized from n-heptane.Yield: 18.8 g (89% of theory) of 2-cyano-4'-methylbiphenyl.

Use Example 42

15 g of 2-chlorobenzonitrile, 14.8 g of p-tolueneboronic acid and 28.9 gof sodium carbonate in 50 ml of p-xylene and 40 ml of DMSO were heatedto 120° C. At 80° C., a mixture of 24.7 mg of palladium(II) acetate and0.55 ml of TPPTS/H₂ O solution (0.6 molar) in 2.5 ml of DMSO was added.After the reaction was complete, the phases were separated. The aqueousphase was washed with 50 ml of xylene. The combined organic phases werewashed with 20 ml of water and subsequently dried over sodium sulfate.The solvent was evaporated and the residue was crystallized fromn-heptane. Yield: 18.0 g (85% of theory) of 2-cyano-4'-methylbiphenyl.

Use Example 43

Cross-coupling of 2-chlorobenzonitrile with 4-tolueneboronic acid.

To prepare the catalyst, 38.8 mg (0.219 mmol) of palladium(II) chlorideand 54.0 mg (0.657 mmol) of sodium acetate in 2.4 ml of DMSO are stirredfor 30 minutes at 23° C. in an argon atmosphere. Subsequently, 1.99 ml(0.875 mmol) of a 0.44 molar aqueous solution of sodium4-diphenylphosphinophenylphosphinate, prepared as described below, areadded and the suspension is stirred at 23° C. for another 30 minutes.Under an argon atmosphere, 30.0 g (0.2181 mol) of 2-chlorobenzonitrile,32.6 g (0.240 mol) of 4-tolueneboronic acid and 16.2 g (70 mol %) ofsodium carbonate are stirred in 120 ml of ethylene glycol. 20 ml ofwater are added and the mixture is heated to 80° C. The above-describedcatalyst suspension is then added and the mixture is heated under refluxfor 5 hours. At 23° C., the mixture is admixed with 100 ml of ethylacetate. The organic phase is separated off evaporated on a rotaryevaporator and fractionally distilled under reduced pressure. This gives31.6 g (75% of theory) of 2-cyano-4'-methlbiphenyl (b.p. 140° C./1.0mbar; m.p. 50° C.).

What is claimed is:
 1. A catalyst system obtained by reacting:a) apalladium(II) compound with; b) a water-soluble phosphine ligand; and c)a sulfoxide or polyhydric alcohol.
 2. A catalyst system as claimed inclaim 1, wherein the polyhydric alcohol is water-soluble and is selectedfrom the group consisting of glycols, glycerol, oligoglycerides, whichmay also be partially esterified, diethylene, triethylene andtetraethylene glycols or polyethylene glycols of the formula (VIII),##STR12## polyhydric alkanols or alkenols, polyhydric cycloalkanols,polyhydric alkanols containing aryl groups, polyhydric aminoalcohols,polyhydric iminoalcohols or 1,1',1"-nitrilotri-2-propanol,1,3,5-tri(2-hydroxyethyl)isocyanuric acid and dihydroxyacetone.
 3. Acatalyst system as claimed in claim 1, wherein the sulfoxide used hasthe formula (IX) ##STR13## where R¹, R² are aliphatic or aromatichydrocabons which may be substituted or linked to one another.
 4. Acatalyst system as claimed in claim 1, wherein the water-solublephosphine ligand is selected from the group consisting oftri-n-alkylphosphines, triarylphosphines, dialkylarylphosphines,alkyldiarylphosphines and heteroarylphosphines provided with carboxylateor carboxylic acid, ammonium, phosphonium, sulfonate or sulfonic acid,phosphonate or phosphonic acid groups or with polyalcohols having asuitable number of hydroxy functions or polyalkylene glycols having asuitable chain length, where the three substituents on the phosphoruscan be identical or different and chiral or achiral and one or more ofthe substituents can link the phosphorus groups of a plurality ofphosphines and part of this linkage can also be one or more metal atoms.5. A catalyst system as claimed in claim 1, wherein the palladium(II)compound used is selected from the group consisting of palladium(II)salts, tetrachloropalladic acid or salts thereof.
 6. A process forpreparing a catalyst system which comprises reacting:a) a palladium(II)compound with; b) a water-soluble phosphine ligand; and c) a sulfoxideor polyhydric alcohol.
 7. The process as claimed in claim 6, whereinwater is added to the reaction.
 8. The process as claimed in claim 6,wherein a solubilizer for the palladium compound is added.
 9. Theprocess as claimed in claim 8, wherein the solubilizer is sodiumacetate.
 10. A method for carrying out C--C linkage reactions using acatalyst system, said catalyst system is obtained by:reacting apalladium(II) compound with a water-soluble phosphine ligand and asulfoxide or polyhydric alcohol, said method comprising cross-couplingan aromatic boron compound with an aromatic halogen compound orperfluoroalkylsulfonate in the presence of a base and said catalystsystem.